Fiber optic switches are known wherein a shutter is driven between the facing ends of a pair of fiber optic cables to break the light path therebetween. A disadvantage of these switches is that the width of the shutter physically limits the narrowness of the gap between the facing cable ends whereby a certain amount of transmission loss between the cables cannot be avoided due to the diverging cone of emitted light. Additionally, because of the shutter, the gap is not hermetically sealed, thus giving rise to further transmission losses due to optical contamination of the cable end faces.